[PATCH] D68006: DSE miscompile when store is clobbered across loop iterations

[Eli Friedman via Phabricator via llvm-commits]

efriedma added a comment.

This is specifically a hole in the calloc() handling, right?  This case can't come up in regular load->store forwarding: the address of the load dominates the load, so the address dominates all the operations between the load and the store, so alias() does the right thing.

We could try to avoid the backedge checking for load->store forwarding. And we could try to be more aggressive if the address is some invariant offset into the calloc.  Maybe not that likely to matter?  What sort of impact does this have on how frequently the transforms triggers?


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https://reviews.llvm.org/D68006